Radiation of relativistic particles for quasiperiodic motion in a transparent medium

Abstract

The radiation of relativistic charged particles for the quasiperiodic motion in a transparent medium is considered. For motion of the general kind the differential probability of the process is obtained. For planar motion the spectral intensity of radiation is found. The different cases of radiation in the medium-filled undulators are studied. In particular, the influence of Cherenkov radiation on the undulator one is discussed. PACS number(s): 41.60.-m

Quantum features of high energy particle incoherent scattering in crystals

“…of the actual width of the Gaussian distribution was introduced by equating the scattering probability at the angles θ > θ c to unity. However, the value (16), in fact, underestimates the angular distribution width (see Fig. 7), since a few scatterings by the angles θ < θ c often result in a multiple scattering angle θ > θ c .…”

“…Despite the large strength of the coherent effects in crystals, all their applications are essentially limited by the incoherent scattering effects relational, but not completely similar, to the scattering process in amorphous media or randomly oriented crystals. Most severely, incoherent scattering by nuclei limits the deflection of negatively charged particles by bent crystals [13,14] as well as both the channeling [1][2][3] and crystal undulator [1,[15][16][17] radiation of the same. That is why, to consider any application of the coherent effects in crystals, it is mandatory to understand and properly treat the incoherent ones.…”

“…This problem is readily solved by the quantum treatment of transverse particle motion [25,26], being, however, both really necessary and practically feasible only at the electron and positron energies of a few dozen MeV and less. However, most of the current investigations are conducted at GeV [13,14,27] and higher [1][2][3][4][5][6][7][8][9][10][15][16][17][28][29][30][31][32][33][34] energies, at which the quantum description of particle motion in the averaged crystal field becomes both redundant and cumbersome, revealing the necessity for the introduction of classical particle motion features into the treatment of their incoherent scattering by the inhomogeneously distributed nuclei. Till now, a redefinition of the scattering impact parameter upper limit R → u 1 [28][29][30][31]35] has been used, which did not take into consideration any incoherent scattering dependence on the transverse particle coordinate, giving, thus, a qualitative estimate only.…”

Optical radiation from channeled relativistic heavy ions in vicinity of the Cherenkov angle

“…In addition, in the case of channeling the intensity of this radiation slightly depends on the azimuthal angle. Although the peculiarities are small, further investigations of channeling influence on the optical radiation from RHI (and other relativistic particles) in the wide range of emission angles are in progress in order to find connections to the normal and anomalous Doppler effects in emission from an oscillator moving in the medium [8][9][10][11][12][13]. The goal of our paper was not to develop new or/and improve the theory developed in [8,9] but apply the relation (3) using numerically obtained (simulated) real trajectories of channeled ions to study the effect of channeling on angular distributions of optical radiation in vicinity of the Cherenkov cone.…”

Electromagnetic field and radiation for a charge moving along a helical trajectory inside a waveguide with dielectric filling

“…Recently the influence of a homogeneous transparent medium on the radiation of relativistic particles in planar undulators is considered in Ref. [24].…”